a comparative study of dexamethasone, granisetron and metoclopramide for prevention of nausea and vomiting after cataract surgery

purpose: to compare the efficacy of granisetron, metoclopramide and dexamethasone in prevention of post operative nausea and vomiting (ponv) after cataract surgery. methods: sixty patients scheduled for cataract surgery with age between 45 to 80 years and with asa class i & ii were enrolled in this clinical trial. the patients were randomly allocated to three 20- person groups. the induction of anesthesia in all groups was similar using the same drugs. granisetron 1 mg iv was administered to patients in the first group and metoclopramide 0.2 mg/kg/iv (max: 10 mg) was administered to the second group at the end of the surgery. in the third group dexamethasone 0.15 mg/kg/iv (max: 8 mg) was used before surgery. patients in all three groups were observed for ponv at defined intervals for 24 hours. results: incidence of ponv during first 6 hours after surgery was 5% in granisetron group, 35% in metoclopramide group and 15% in dexamethasone group. only the difference between granisetron and metoclopramide groups was statistically significant (p= 0.01). incidence of late ponv (6-24 h) was 5% in granisetron group, 30% in metoclopramide group and zero in dexamethasone group. this difference was statistically significant (p<0.01). conclusion: granisetron is more effective than metoclopramide in prevention of ponv after cataract surgery. granisetron and dexamethasone are more effective than metoclopramide in prevention of late ponv after cataract surgery.